I've been watching the show Emergency on DVD and there are often TV's shown in the scene.
The one in Station 51 changes over the course of the show but in 1976 it was a metal cased Zenith color with the controls along the bottom, probably early 70's, in Rampart there's an Avanti but it's brown instead of the usual white.
In the latest episode, circa 1976, there's a Zenith? in the background with a Pong game running.
I remember when Pong came out and what a big deal it was then, games have advanced a little since then.
There was a set (Magnavox?) that had Pong built in, it was obsolete almost as soon as it hit the stores.